Boss bypass circuit without buffers, any good?

[mac]

I wonder if the Boss bypass circuit (no idea how the heck it works!) without the buffers is a good idea when you have trouble getting good true bypass switches.

I have two Boss pedals, which I bought just because they were very very cheap, and in bypass mode they alter the sound in a way I dont like.
My question is if this tone change is due mainly to the buffers or to the bypass circuit?

mac

[edvard]

Should work fine.
The stand-alone DOD switch circuit floating around the 'net (which also uses FETs as the switch elements) shows no buffers either, so you should be ok.
The only thing to keep in mind is that without buffers, you'll be straight feeding capacitor inputs, so it would be wise to add pull-down resistors at the head and tail.
Something like 1Meg to ground should suffice.

[earthtonesaudio]

All the switches the signal passes through in "bypass" mode have at least one, and usually two bias resistors.  If the signal is going through multiple switches this parallel combination can add up to a low-impedance load on the dry signal that will reduce volume and change the frequency response. 

For example if the dry path is two switches, with a total of two bias resistors and two in/out pull-down resistors (all 1M) then the resistive load on the guitar is 250k.

[petemoore]

  Yes to the title.
 
  Maybe since we aren't talking about the relevant circuit.
  As in 1 case could be I've just never heard wind of true bypass Boss circuit.
  Completely unrelated to that...
  The circuit in question goes beyond look at the circuit we're calling boss.
  So...it'd help to see the circuit schematic of the boss, and then to know what the rest of the relevant' circuit consists of.
  By relevant I mean what is plugged into boss or what boss plugs into may have differed response w/Jfet source follower compared to raw boss.

[trjones1]

Should work fine.
The stand-alone DOD switch circuit floating around the 'net (which also uses FETs as the switch elements) shows no buffers either, so you should be ok.

Yes, but isn't the DOD bypass notoriously lousy and tone sucking?  I've never been able to keep a DOD pedal for long because they just destroy your bypassed tone.

[mac]

The control circuit is connected to the gates of the fets. Since the gate is "almost isolated" from the drain and source I guess that it does not suck much tone...
How the control circuit works I dont know yet, but from the schem above it looks like the transistors have two states, on and off, which are changed every time the footswitch is pressed. When one transistor is on the other is off. Those states (like in quantum physics!) control the gates, making the channel resistance of fets q6 and q7 go low/high, and high/low for q8, thus working like a switch.

mac

[R.G.]

How the control circuit works I dont know yet,

Try reading Geofex.com.

In this case, http://geofex.com/Article_Folders/bosstech.pdf, the Technology of Boss and Ibanez bypass circuits.

[mac]

Try reading Geofex.com.

In this case, http://geofex.com/Article_Folders/bosstech.pdf, the Technology of Boss and Ibanez bypass circuits.

That´s the one I was looking for, thanks RG.

mac